Process of packaging sutures



April s. B. BRADSHAW ,7 7

XROCESS OF PACKAGING SUTURES Filed July 27; 1937 gwuc/wfo o 5mm; y 6. 59405/14 w Patented Apr.

PATENT OFFICE PROCESS OF PACKAGING SUTURES Sidney B. Bradshaw, Chicago, Ill., assignmto- Armour and Company, Chicago, 11]., a corporation of Illinois Application July 27, 1937, Serial No. 156,001

8 Claims.

This invention relates to processes of sterilizing sutures or ligatures of the non-boilable type, namely those which are packaged in sealed tubes containing an alcoholic tubing fluid, and it com- "-prises processes wherein such sutures are first wound or coiled, then inserted in a glass tube or similar container, asmall amount of toluene or other aromatic or aliphatic hydrocarbon fluid having a boiling point below the sterilizing temperature added thereto, the open end of the tube then closed with a plug of cotton or similar material, the tube and its contents subjected to sterilization in an autoclave, the temperature thereof rising to a point above the boiling point of the hydrocarbon fluid so that during sterili za tion the hydrocarbon fluid is vaporized off, the alcoholic tubing fluid thereafter added to the tube and contents, the cotton plug removed, and theopen end of the tube scaled up.

2 In the packagingof cat-gut sutures or ligatures of the'non-b'qilable variety it is common practise to include in the tube containing the ligature an alcoholic tubing fluid which frequently contains potassiuriiwmercuric iodide or other 'antiseptic. The conventional method of sterilizing such suture packages prior to adding the tubing fluid consists in first inserting the coiled suture in a glass. tube which is sealed at one end, then adding';a'very high boiling point by- -drocarbon fluid such as cumol, and then subjecting the package to a sterilizing temperature in a suitable autoclave. After sterilization the cumol must be drained from the tube under aseptic technique, the tubing fluid added, and

35 the tubesealed;

One outstanding disadvantage in this method of sterilizing non-boilable sutures is that the hydrocarbon sterilizing fluid must be drained from the tube before the alcoholic tubing fluid 4 can be added. In the case of boilable sutures it is common practise to place the coiled suture in the tube, cover it with the tube arid then subject the package to the sterilizing temperature. In this case the liquid 45 in the presence of which the suture is sterilized becomes the tubing fluid. Such methods of sterilizing boilable sutures are disclosed in the Davis Patents 1,168,173 and 1,168,174. No one, how- .ever, has hitherto been able to package non boilable sutures in sealed glass tubes containing an alcoholic tubing fluid withou flrst draining the cumol or other sterilizing fl d which must j be present during sterilization in orderfor the physical character of the suture,to be preserved.

I have now discovered ways of packaging nonluene or xylene, seal boilable sutures and ligatures in. steiile glass tubes, or similar sealed containers, by means of which I am able to avoid the disadvantages inherent in present processes. My invention is based on the concept of using for the sterilizing fluid an aliphatic or aromatic hydrocarbon, such as toluene or xylene, ortother mixtures of hydrocarbons, which boils below the maximum sterilizing temperature, and so assembling the suture package that during the sterilizing procl0 ess the sterilizing fluid is volatilized from the tube containing the s ture. Since the sterilizing fluid volatilizes co pletely by the time the sterilization is finished, I can directly flll the sterilized tubes with the tubing fluid without removing the cotton or similar plugs. Thus I avoid the necessity for the separate draining operation at present employed.

In order that my invention may be more clearly understood I use the language sterilizing fluid" to mean that fluid in thepresence of which the suture is sterilized, and use the words tubing fluid to mean that fluid added to the sterilized non-boilable suture before sealing off the tube. The tubing fluid I .use may be the same as that hitherto used with non-boilable sutures, or it may be of-different composition. An example of a commonly used tubing fluidconsists of 97 parts by volume of absolute alcohol and 3 parts by volume of sterile water. Various antiseptics such as mercuric iodide and potassiummercuric iodide are frequently dissolved in the alcohol. I make no claim to any particular tubing-fluid except that it is one customarily used-with non-boilable sutures. Consequently, 86 it diflers from xylene or toluene used as a tubing fluid in connection with boilable sutures.

The sterilizing fluid which I use is a hydrocarbon fluid having a boiling point less than about 320 F. or 160 0. since this is'the usual 40 sterilizing temperature. If higher sterilizing temperatures are used the sterilizing fluid can have a higher boiling point, but ordinarily the sterilizing fluids which operate best in my invention are toluene which boils at 232 F. and-Q the xylenes. Various mixtures of toluene and xylene can, of course, be used and I can even use benzene, but because of its low boiling point and high volatility it does not remain as long in contact with the suture during sterilization, It is advantageous that the sterilizing liquid be one which will evaporate rather slowly during the sterilization so-as to furnish a heat conducting medium as long as possible, but it should be completely evaporated by the time the autoclaving period is finished. Aliphatic hydrocarbons,

such as hexane, heptane, octane and nonane and During the sterilization operation the volatile assembly put inthe autoclave.

tubing fluid vaporizes and the vapors thereof readily pass through the cotton plug. When the tube is withdrawn from the sterilizer it is still sealed although temporarily, with sterile cotton, and the cotton plug need not be withdrawn from the tube until the open end is about to be sealed. The tubing fluid can be readily introduced into the sterile glass tube through a. sterile tube .or dispensing nozzle of rather small diameter by inserting the nozzle into the tube between the inside periphery thereof and the cotton plug. The dispensing nozzle is, of course, connected with a supply of the sterile tubing fluid and the amount of tubing fluid introduced in the tube can be carefully controlled by means of a pinch-cock. p a

In order that. my invention may be more clearly understood I illustrate on the attached sheet of drawings the operative technique to be used in preparing. my 'st'erile'tubes of non-boilable sutures. 7 1

In the drawing Figure 1 is a side view of a suture tube containing the suture and a porous plug, and Figure 2 illustrates how tubing fluid is introduced into'the tube without removing the cotton plug therefrom. Figure 2 is a side view of the arrangement of a container for the tubing fluid and the means of introducing the fluid into the suture tube.

Referring more particularly to Figure 1 of the drawing, I indicate therein a. glass tube l containing the suture 2, the open end of the tubing beiiig plugged with a cotton plug 3. The suture can first be wound uponone of the reels conventional. in the art, the reel inserted in the tube, sterilizing fluid 4 being then added, and the tube closed with cotton plug-3. The package is then inserted in a sterilizer or autoclave of the type used for sterilizing articles of this nature. Usually a number of the glass tubes are placed on a frame-work or basket and the whole The autoclave is then closed and heated to a temperature of about 300 to 320 F. It takes about one hour for th e autoclave to heat up to the stated temperature. It is held at about 320'" F. for about another hour and then allowed to cool down. At about 320 F. the pressure in the autoclave will;

reach about 45 pounds per square inch. n

The glass tubes are then removed and the tubing fluid added. Figure 2 shows the method used for filling the tubes with tubing fluid. The tube is held in one hand and a sterile hollow needle or dispensing nozzle 5 is pushed down along the inside periphery of the tube between the cotton plug and the tube. Nozzle 5 is connected by -a flexible tube 6 to a large glass jar 1 containing the sterile tubing fluid 8. A simple pinch-cock 9 enables the operator to start or stop the delivery' of tubing fluid to the nozzle. The tubing fluid is delivered to the tube until about onehalf the suture coil is covered.

Thereupon the suture package is transferred to another operative who removes the cotton plug with a pair of long sterile forceps and immediately puts the upper open end of the tube between two opposed gas flames and seals of! the open end of the tube. The sealing operation is done so quickly that the alcohol tubing fluid has no chance to evaporate, and thus there is no fire hazard involved. 7 i

In sealing ofi the tube the operator, as stated, puts the upper, open end of the tube in the path of two opposed gas flames at a point about onehalf inch or so below the end of the tube. The tube is rotated in the flame and the edge of the open end grasped withiorceps so that when the glass of the tube has softened sufilciently it can vbe pulled out to form a seal. This method well understood in the art.

It will be apparentthat using toluene, or xylene or similar aromatic or aliphatic hydrocarbon for the sterilizing fluid has many advantages. These substances can be obtained in a high state oil-purity. They leave no residue on evaporation, they are fat solvents and defat the suture. Thesuture can be dehydrated during the course of sterilization so that no separate dehydrating step is necessary, although the suture in its glass tube can, of course, be dehydrated as a separate operation priorto add ing the sterilized fluid. Moreover. the steriliz ing fluid of my invention maintains the desiredphysical characteristics of the suture intact and does not permit any chemical decomposition to occur. So far as I am aware I am the first to describe any method of preparing sterile tubes of non-boilable sutures containing-the usual tubing fluids used with this type of -suture material withoutthe necessity for removing the sterilizing fluid before adding the tubing fluid.

It will be understood, of course, that various mixtures of liquid aromatic or aliphatic hydrocarbons can be used as the sterilizing fluidso long as their volatility and amount is correlated with the sterilizing temperature and time of sterilization so that the fluid will slowly evaporate during the sterilization and will have completely evaporated by the time the sterilization is. completed. It will also be understood that the autoclaves used in this art have a large vapor space above the suture tubes and that, during cooling down after sterilization the sterilizing fluid condenses to a liquid in a space below the basket assembly carrying the tubes. Consequently, none of the sterilizing fluid condenses to a liquid within the suture tube. The sterilizing fluid thus collected can be drawn off and used for treating another batch of tubes if desired.

Although it is one of the features of my invention to perform the sterilization and filling of the tubular suture container with tubing fluid while the tube is temporarily closed with a removable plug of fibrous material, I can, of course, sterilize the tube and contents without temporarily closing the open end of the tube. Consequently, in broadest aspects my invention comprises sterilizing in the presence of a hydrocarbon fluid which is allowed to evaporate out of the container during sterilization.

Having thus described my invention, what I claim is: 1

l. The process of sterilizing and filling tubes of non-boilable sutures with tubing fluid which comprises sterilizing the suture in the presence of a point below the sterilization temperature, the suture being disposed during sterilization in a tubular container sealed at one end and temporarily closed at the other end by a removable plug of porous fibrous material so that during hydrocarbon sterilizing fluid'having a boiling 7 sterilization the sterilizing fluid can evaporate completely from the container, and then adding tubing fluid to the container and sealing off the open end thereof.

2.-' Ihe process of sterilizing and filling tubes of non-boilable sutures with tubing fluid which comprises sterilizing the suture in the presence of a. hydrocarbon sterilizing liquid having a boiling point below the sterilization temperature, the suture being disposed in a tubular container sealed at one end and temporarily closed at the other lizing fluid is toluene.

4. The process as in claim "2 wherein the sterilizing fluid is toluene. I

5. The process which comprises sterilizing a non-boilable suture disposed in a tubular container having one end open to the atmosphere and containing a hydrocarbon having a boiling point below the sterilization temperature so that during sterilization the hydrocarbon can evaporatefrom the container, then adding an alcoholic tubing fluid to the container and sealing the open end of the container.

6. The process as in claim 5 wherein the hydrocarbon is toluene.

7. In the art of sterilizing non-boilable sutures the steps comprising providing a non-boilable suture disposed in a tubular container in which the suture "is to be sealed, said container being open at one end to the passage of vapors therethrough, said container containing a hydrocarbon having a boiling point below the sterilizing temperature, then heating the container and contents to a sterilizing temperature so that during sterilization the hydrocarbon fluid is evaporated from the container, addi'ng tubing fluid, and then sealing the open end of the container.

8. The process as in claim 7 wherein the hydrocarbon fluid is toluene ;l 

